1. Field of the Disclosure
This disclosure relates generally to apparatus and methods for completing a wellbore for the production of hydrocarbons from subsurface formations, including fracturing, sand packing and flooding formation zones.
2. Background of the Art
Wellbores are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Modern wells are drilled to great well depths, often more than 1500 meters (about 15,000 ft.). Hydrocarbons are found in traps at different depths in subsurface formations. Such sections of the formation are referred to as reservoirs or hydrocarbon-bearing formations or zones. Some formations have high mobility, which is a measure of the ease of hydrocarbon flow from the reservoir into a well drilled through the reservoir under natural downhole pressures. The hydrocarbons trapped in low mobility formations are unable to move with ease from the reservoir into the well. Stimulation methods are typically employed to improve the mobility of the hydrocarbons through such reservoirs. One such method, referred to as hydraulic fracturing (also referred to herein as “fracing” or “fracking”), is often utilized to create cracks in the reservoir to enable the fluid from the formation (formation fluid) to flow into the wellbore. In hydraulic fracing, a treatment fluid (also referred to as the “frac fluid,” which typically is a mixture of water and an additive, such as guar, and a proppant, such as synthetic sand) is supplied under pressure to create cracks in the formation and to fill such cracks with the proppant. Such a method is also referred to herein as frac/pac.
To fracture a zone, an assembly containing an outer string (also referred to herein as the “permanent string”) with an inner string (also referred to herein as the “service string” or the “running tool”) therein is run in or deployed in the wellbore, wherein the wellbore may be an open hole or cased hole. The outer string typically includes a sleeve port that allows the frac fluid to flow to the annulus between the outer string and the perforations in the wellbore. The inner string includes devices attached to a tubing to operate various devices in the outer string and a port or device commonly referred to as the “frac port” that allows the frac fluid supplied from the surface under pressure to flow from the inner string to the perforations via the frac sleeve.
Frac ports typically contain a number of radial openings that supply the treatment fluid across the sleeve port, which also has multiple radial openings. In such port configurations, the frac fluid flows around the entire circumference of the outer string at same pressure. In some formations, it may be desirable to direct the supplied frac fluid in a particular direction to cause fractures along such radial direction to enhance fracturing. In horizontal wells, it may be desirable to fracture the formation along the high side of the wellbore for enhanced recovery of oil from such zones.
The present disclosure provides apparatus and methods for orienting a frac port along a desired radial direction for the treatment of wellbore.